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1.
The toxicity of folic acid (PGA) was studied in different inbred strains of mice. LD50 values of PGA by the i.p. route showed a unique toxicity pattern. In some strains, convulsions, ataxia and weakness were observed. Histopathological study in strains S/RVCri, BDF1, DBA/2 and DBA/2fNCri showed acute renal tubular necrosis. 相似文献
2.
B. D. Singh Ravi Prakash Singh R. B. Singh 《Cellular and molecular life sciences : CMLS》1981,37(4):363-364
Summary 2 tall and 7 dwarf strains of rice were sprayed with 0 or 40 g ml–1 GA3, 4 dwarf strains responded to exogenous GA3, and showed a markedly lower endogenous gibberellin content than the tall strains, while 2 dwarf strains did not respond to GA3 application and had considerably higher endogenous gibberellin levels than the tall ones. Amylase activity in germinating seeds showed a significant negative correlation with the endogenous gibberellin content. 相似文献
3.
W. G. Jaffé 《Cellular and molecular life sciences : CMLS》1962,18(2):76-77
Summary Soluble proteins from black beans (Phaseolus vulgaris) have been separated into 4 fractions, one soluble in 1% NaCl-solution and 3 water soluble. The latter were separated by ammonium sulfate fractionation. The haemagglution of these fractions is compared with their toxicity in mice when applied by intraperitoneal injection. The LD50 of the most active fraction was about 50 mg/kg. When used in mice of different strains, the toxicity was not the same while the blood cells were agglutinated by the same final concentration. Crotonoil-induced papilloma-bearing mice were slightly more resistant than normal animals. 相似文献
4.
Summary The increasing environmental and occupational exposure of populations to cadmium creates the need for biological indicators of cadmium exposure and toxicity. The advantages and disadvantages of monitoring blood cadmium, urinary, fecal, hair, and tissue cadmium, serum creatinine, 2-microglobulin, 1-antitrypsin and other proteins, and urinary amino acids, enzymes, total proteins, glucose 2-microglobulin, retinol-binding protein, lysozyme, and metallothionein are discussed. It is concluded that urinary cadmium, metallothionein and 2-microglobulin may be used together to assess cadmium, exposure and toxicity. 相似文献
5.
Zusammenfassung DBA/2 Mäuse wurden nach Injektionen mit SL2 Zellen mit allogenen, immunen und hyperimmunen Exsudat-Zellen aus dem Peritonealraum behandelt. Diese Behandlung ergab eine Eliminierung von 2×106 SL2 Zellen. 相似文献
6.
Summary The morphology and internal structure of Influenza A2 (Hongkong) virus is described. This virus has the same morphological characteristics as previously isolated Influenza A0, A1; and A2 strains. Evidence is also presented that this influenza virus appears in a filamentous form in human throat washings. The reasons for the virus to be a filamentous or a spherical particle are discussed.
Die Arbeit wurde vom Schweiz. Nationalfonds unterstÜtzt. 相似文献
Die Arbeit wurde vom Schweiz. Nationalfonds unterstÜtzt. 相似文献
7.
The central role played by the αIIbβ3 receptor in platelet aggregation, and hence in platelet thrombosis, has led to the development of a number of parenteral
and oral glycoprotein (GP) IIb/IIIa inhibitors for use in cardiovascular disease states, such as acute coronary syndromes
and stroke. The predominant effect of these agents is to inhibit platelet aggregation, although studies of αIIbβ3 receptor function and various GP IIb/IIIa inhibitors have demonstrated the potential for these agents to produce effects
on other aspects of platelet function, in addition to non-platelet effects. Overall, clinical studies have demonstrated an
impressive beneficial effect for parenteral agents in reducing ischemic complications following percutaneous intervention,
and a more modest beneficial effect in the treatment of patients with acute coronary syndromes. Trials with oral GP IIb/IIIa
inhibitors in similar patient populations have demonstrated toxicity, manifested by an increased mortality in treated patients.
Increased understanding of molecular aspects of both αIIbβ3 receptor function and the effects of GP IIb/IIIa inhibition may help explain some of the inconsistency in recently reported
clinical studies with parenteral agents, and the frank toxicity of oral agents. Such studies may also hold the key to the
development of newer agents with enhanced therapeutic benefit.
Received 10 September 2001; received after revision 22 October 2001; accepted 2 November 2001 相似文献
8.
H. R. Frischknecht B. Siegfried P. G. Waser 《Cellular and molecular life sciences : CMLS》1988,44(6):473-481
Summary Three animal models, based on genetic differences in endogenous opioid peptides and opioid receptors, are described. Obese mice and rats, whose pituitary opioid content is elevated, may be used to investigate eating disorders. Recombinant inbred strains of mice, which differ in brain opioid receptors and analgesic responsiveness, can be used for study of opioid-and nonopioid-mediated mechanisms of pain inhibition. Individual reactivity to opioids can be examined in C57BL/6 and DBA/2 inbred strains of mice. A model that combines a variety of opioid effects is offered and suggests the existence of a genetically determined dissociation of opioid effects on locomotor activity and pain inhibition. In addition, stimulatory locomotor responses in the C57BL/6 reaction type are linked to a high risk of drug addiction and facilitatory effects on adaptive processes, while high analgesic potency in the DBA/2 reaction type is accompanied by a low proneness to drug abuse and amnesic properties of opioids. 相似文献
9.
Three animal models, based on genetic differences in endogenous opioid peptides and opioid receptors, are described. Obese mice and rats, whose pituitary opioid content is elevated, may be used to investigate eating disorders. Recombinant inbred strains of mice, which differ in brain opioid receptors and analgesic responsiveness, can be used for study of opioid- and nonopioid-mediated mechanisms of pain inhibition. Individual reactivity to opioids can be examined in C57BL/6 and DBA/2 inbred strains of mice. A model that combines a variety of opioid effects is offered and suggests the existence of a genetically determined dissociation of opioid effects on locomotor activity and pain inhibition. In addition, stimulatory locomotor responses in the C57BL/6 reaction type are linked to a high risk of drug addiction and facilitatory effects on adaptive processes, while high analgesic potency in the DBA/2 reaction type is accompanied by a low proneness to drug abuse and amnesic properties of opioids. 相似文献
10.
Summary The LD50 of DMN was determined in groups of mice in the presence of inhibitors of DMN demethylase. Piperonyl butoxide, dibutylnitrosamine and nitrososarcosine had no effect on the acute toxicity of DMN. Diethylnitrosamine and DMN were markedly synergistic. All mice treated with 100 mg/kg diethylnitrosamine and 10.7 mg/kg DMN died. These results suggest that DMN demethylase may not be involved in theaacute toxicity of DMN.We thank Dr.D. B. Couch, Mr.E. J. Greene and Dr.A. E. Munson for their technical assistance. 相似文献
11.
M. Aglietta A. Stacchini F. Sanavio W. Piacibello 《Cellular and molecular life sciences : CMLS》1985,41(3):375-376
Summary The effect of 2 H2 receptor antagonists (ranitidine and cimetidine) on the in vitro growth of human granulomonopoietic precursors (CFU-GM) was studied. Ranitidine, although having an anti H2 receptor activity much greater than that of cimetidine, displays the same toxicity for CFU-GM.Acknowledgments. This work was supported by CNR, Rome, PFCCN and AIRC, Milan. 相似文献
12.
Genetic control of hippocampal cholinergic and dynorphinergic mechanisms regulating novelty-induced exploratory behavior in house mice 总被引:1,自引:0,他引:1
J H van Abeelen 《Experientia》1989,45(9):839-845
Neurobehavioral genetics endeavors to trace the pathways from genetic and environmental determinants to neuroanatomical and neurophysiological systems and, thence, to behavior. Exploiting genetic variation as a tool, the behavioral sequelae of manipulating these neuronal systems by drugs and antisera are analyzed. Apart from research in rats, this paper deals mainly with the genetically-influenced regulation in mice of exploratory behaviors that are adaptive in novel surroundings and are hippocampally-mediated. Special attention is paid to neuropeptidergic, GABAergic, and cholinergic synaptic functions in the mouse hippocampus. The behaviorally different inbred mouse strains C57BL/6 and DBA/2 show opposite reactions (reductions and increases, respectively, in exploration rates) to peripheral and intrahippocampal injections with agents that interfere with peptidergic, cholinergic, and GABAergic neurotransmission. These findings can be explained by an interdependent over-release of opioids, arrested GABA release, and excess acetylcholine in the hippocampal neuronal network of DBA/2 mice, as compared to C57BL/6 mice where these systems are functionally well balanced. Very similar results have been obtained with the lines SRH and SRL, derived from C57BL/6 and DBA/2, and genetically selected for rearing behavior. Most probably, the opioids act to disinhibit exploratory responses. An additional genetic approach is mentioned, in which four inbred mouse strains and one derived heterogeneous stock are used for estimating genetic correlations between structural properties of the hippocampal mossy fibers and levels of hippocampal dynorphin B, on the one hand, and frequencies of exploratory responses to environmental novelty, on the other. 相似文献
13.
M. Sedqi M. Delaforge D. Mansuy B. Martin P. Jollès D. Migliore-Samour 《Cellular and molecular life sciences : CMLS》1995,51(8):790-798
The sex-dependent effect of lauroyl-L-Ala-D--Glu-L,L-A2pmNH2 (LtriP, RP 56142) on hepatic microsomal cytochromes P 450 (cyt P 450) was studied in three mouse strains NMRI, C3H/OuJ and C3H/HeJ. In NMRI and C3H/OuJ, strains which are responsive to bacterial lipopolysaccharides (LPS-responsive), regardless of the sex of the mouse, significant decrease in the amount of cyt P 450 was observed after LtriP treatment, with a concomitant reduction in ethoxyresorufin-O-deethylase (cyt P 450 1A-dependent) and 7-ethoxycoumarin-O-deethylase activities. This was not seen in C3H/HeJ (LPS-hyporesponsive) mice. These effects may be related to LtriP-dependent cytokine induction, since neither LtriP nor LPS stimulated interleukin-1 (IL-1) secretion by C3H/HeJ macrophages. 11- and 12-hydroxylations (11- and 12-OH) of lauric acid were compared in C3H/OuJ and C3H/HeJ mice. LtriP depressed the total enzymatic conversion of lauric acid in the two strains without modification of the 11/12-OH ratio for C3H/OuJ or male C3H/HeJ mice. However, in females C3H/HeJ mice this decrease was particularly significant and concerned especially the 12-OH activity (a marker of cyt P450 4A family). Although males of the three strains were more sensitive to irradiation than females, LtriP exerted a sex-independent radioprotection on NMRI and C3H/OuJ mice. Its radioprotective effect was illustrated by the preservation of all the enzymatic activities studied in treated NMRI mice, contrary to irradiated control animals. In contrast, for the C3H/HeJ strain, males were not protected by LtriP treatment and, furthermore, females showed a marked sensitization to irradiation.The effects in CH3/HeJ strain implicate LtriP in the control of cyt P 450 induction and of sensitivity to irradiation independently of IL-1 induction. 相似文献
14.
J. H. F. van Abeelen 《Cellular and molecular life sciences : CMLS》1989,45(9):839-845
Summary Neurobehavioral genetics endeavors to trace the pathways from genetic and eenvironmental determinants to neuroanatomical and neurophysiological systems and, thence, to behavior. Exploiting genetic variation as a tool, the behavioral sequelae of manipulating these neuronal systems by drugs and antisera are analyzed. Apart from research in rats, this paper deals mainly with the genetically-influenced regulation in mice of exploratory behaviors that are adaptive in novel surroundings and are hippocampally-mediated. Special attention is paid to neuropeptidergic, GABAergic, and cholinergic synaptic functions in the mouse hippocampus.The behaviorally different inbred mouse strains C57BL/6 and DBA/2 show opposite reactions (reductions and increases, respectively, in exploration rates) to peripheral and intrahippocampal injections with agents that interfere with peptidergic, cholinergic, and GABAergic neurotransmission. These findings can be explained by an interdependent over-release of opioids, arrested GABA release, and excess acetylcholine in the hippocampal neuronal network of DBA/2 mice, as compared to C57BL/6 mice where these systems are functionally well balanced. Very similar results have been obtained with the lines SRH and SRL, derived from C57BL/6 and DBA/2, and genetically selected for rearing behavior. Most probably, the opioids act to disinhibit exploratory responses. An additional genetic approach is mentioned, in which four inbred mouse strains and one derived heterogeneous stock are used for estimating genetic correlations between structural properties of the hippocampal mossy fibers and levels of hippocampal dynorphin B, on the one hand, and frequencies of exploratory responses to environmental novelty, on the other. 相似文献
15.
G. Brambilla M. Cavanna S. Parodi L. Baldini 《Cellular and molecular life sciences : CMLS》1970,26(10):1140-1141
Riassunto I dati esposti indicano che l'incremento del numero dei loci dell'istocompatibilità ai quali differiscono i due ceppi di topi «inbred» DBA/2 e C57BL/6 è inversamente proporzionale al tempo trascorso dal trapianto, ed è maggiore nelle femmine.
This investigation was supported by a grant of the Consiglio Nazionale delle Ricerche. 相似文献
This investigation was supported by a grant of the Consiglio Nazionale delle Ricerche. 相似文献
16.
17.
M. N. Schwarcz de Tarlovsky S. G. Goijman M. P. Molina Portela A. O. M. Stoppani 《Cellular and molecular life sciences : CMLS》1990,46(5):502-505
Several 4-(aminomethylisoxazolyl)-1,2-naphthoquinones inhibited growth and DNA synthesis inTrypanosoma cruzi and stimulated O2 uptake and
generation by the parasite epimastigotes and their mitochondrial and microsomal membranes; these results support the idea that oxygen radicals play a role in quinone toxicity. Maximal effects on respiration and
generation were observed with antimycin-inhibited cells. Similar results as well as stimulation of H2O2 production were obtained withCrithidia fasciculata despite the presence of catalase in this organism.Acknowledgments. This work was aided by grants from the University of Buenos Aires, the Scientific Office of the American States Organization and CEDIQUIFA (Buenos Aires). S.G.G. and M.P.M.P. are Research Fellows and A.O.M.S. is Career Investigator of CONICET (Argentina). L. T. Viñas and M. G. Gutierrez lent able technical assistance. 相似文献
18.
J. W. M. Lagerberg J. VanSteveninck T. M. A. R. Dubbelman 《Cellular and molecular life sciences : CMLS》1997,53(3):257-262
The fluorescent dye Merocyanine 540 (MC540) is often used as a probe to monitor the molecular packing of phospholipids in
the outer leaflet of biomembranes. In a previous study we showed that the increased staining of erythrocytes with a perturbed
membrane structure was mainly due to an increase in the fluorescence yield of cell-bound MC540, rather than to an increase
of the number of bound molecules. Erythrocytes and ghosts exposed to continuous fluxes of H2O2 exhibited pronounced lipid peroxidation. Further, red blood cells subjected to this form of oxidative stress also showed
increased staining with MC540. It appeared that this was caused by a strong increase in binding of MC540, together with a
slight red shift of the fluorescence emission maximum and a small increase in the fluorescence yield of bound MC540. The changed
MC540 binding characteristics were not observed when lipid peroxidation was suppressed by the presence of the antioxidant
BHT in the incubation medium. However, open ghosts exposed to H2O2 showed no increase of MC540 binding, excluding a direct involvement of lipid peroxidation. Measurement of fluorescence emission
spectra and gel filtration studies showed that MC540 can bind to H2O2-exposed hemoglobin. Experiments with erythrocytes lysed in hypotonic medium after exposure to H2O2 revealed that peroxidation of lipids with H2O2 induced a non-specific permeabilization of the plasma membrane to MC540, thereby allowing MC540 to bind to the oxidatively
denatured, more hydrophobic hemoglobin. These results indicate that conclusions about packing of phospholipids in the outer
leaflet of the membrane based on increased MC540-staining should be drawn with care.
Received 27 September 1996; received after revision 5 November 1996; accepted 27 November 1996 相似文献
19.
Summary Homogenates from T. cruzi epimastigotes produced 3.4 pmoles H2O2/min 106 cells, as detected by the cytochrome c peroxidase assay. Addition of NADH or NADPH increased H2O2 production by a factor of 3 and 5, respectively. When supplemented with NADH and NADPH, the mitochondrial, microsomal, and supernatant fractions produced H2O2, the soluble fraction and the mitochondrial membranes being apparently the main generators of H2O2. The epimastigote homogenates showed cyanide-sensitive superoxide dismutase activity, equivalent to 0.28 g bovine superoxide dismutase per mg homogenate protein.This investigation was supported by grants from Consejo Nacional de Investigaciones Cientificas y Técnicas (CONICET) Argentina and the Scientific Office, American States Organization.Career Investigator of CONICET. 相似文献
20.
M. Steinemann S. Steinemann J. Fakler 《Cellular and molecular life sciences : CMLS》1986,42(5):577-579
Summary The-amylase gene ofDrosophila miranda is located on the X2-and on the neo-Y-chromosome, both developing sex chromosomes. Crosses between strains carrying different electrophoretically distinguishable alleles of the-amylase gene were performed. Females of the F1 offspring showed the expected heterozygosity, while the males proved to be hemizygous for this locus. Only the gene on the X2-chromosome is expressed, whereas the corresponding gene on the neo-Y-chromosome is not. Estimates of the-amylase activity in crude homogenates of male and female flies suggest strongly that the-amylase gene is dosage compensated inD. miranda. In contrast to this situation, in all otherDrosophila species the-amylase allele is autosomal and hence not dosage compensated.Acknowledgments. We would like to thank Betty C. Moore, for the kind supply ofD. miranda strains. For the help and advice in the electrophoretic separation of the-amylase variants we are indebted to Dr W. Pinsker. This work was supported by a grant from the Fonds zur Förderung der wissenschaftlichen Forschung, P5413 (Austria). 相似文献